Diffusion of a substance across the cell membrane may be influenced by all of the following except
A) the availability of ATP.
B) the presence of membrane channels for the substance.
C) its charge of the substance.
D) its concentration gradient.
E) its lipid solubility.

Question

Quizplus · Accepted Answer

ATP is not directly involved in the process of diffusion across the cell membrane, which relies on the passive movement of molecules from an area of high concentration to an area of low concentration. However, ATP is required for active transport, which involves the movement of molecules against their concentration gradient.

Diffusion of a Substance Across the Cell Membrane May Be